Method and apparatus for surfaceblasting with abrasive



May 1 l, 1965 J. B. eoss ETAL 3,182,425

METHOD AND APPARATUS FOR SURFACE-BLASTING WITH ABRASIVE Filed. Oct. 8, 1962 2 Sheets-Sheet 1 sY r M United States Patent 3,182,425 METHOD AND APPARATUS FOR SURFACE- BLASTHNG WITH ABRASIVE John B. Goss and Robert H. E. Schmidt, both of 2604 Knoblock St., Houston 23, Tex. Filed Oct. 8, 1962, Ser. No. 228,963 10 Claims. (Cl. 518) This invention relates to new and useful improvements in methods and apparatus for surface-blasting with sand or other abrasive materials.

In industrial and commercial applications today, many surfaces are cleaned and prepared for coatings by blasting such surfaces with sand or other abrasives. Normally, the sand or abrasive which is used is specifically selected and classified for blasting usage.

Prior to this invention, the method and apparatus for handling the abrasive from its source to its point of usage for surface-blasting has been relatively complex and very costly. Typically, the prior practice involved the filling of sacks of paper or other disposable material at the source of the abrasive classification, then the sack-s were stacked, usually by hand, on pallets. The pallets where thereafter carried by fork lift trucks or other transportation to the railroad cars or truck transports for shipment to the customer. At the customers point of usage, the sacks were carried to a sand blasting pot where they were lifted manually to the top of the pot hopper and then the sand was dumped into the pot hopper for use in the blasting operation.

' An object of the present invention is to provide a method and apparatus for the handling and use of said or other abrasive in surfaceblastin-g which is simplified as compared to prior practice for thereby reducing the manual handling and the cost heretofore involved in surfaceblasting operations.

An important object of this invention is to provide a new and improved method and apparatus wherein a pressurizable bag is filled with an abrasive material, transported to its point of use, and thereafter pressurized for dispensing the abrasive, whereby multiple handling of the abrasive is minimized.

Another object of this invention is to provide a new and improved pressurizable flexible bag which is capable of being filled with sand or other abrasive material for transportation and then, after discharge of the material therefrom returned in a flattened deflated condition for subsequent use.

A further object of this invention is to provide a new and improved apparatus for discharging sand or other abrasive material at a high velocity against surfaces for cleaning or otherwise preparing same.

The preferred embodiment of this invention will be described hereinafter, together with other features thereof, and additional objects will become evident from such description.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and where- FIG. 1 is an elevation illustrating one form of apparatus which may be used for dispensing sand or other material in carrying out the process of this invention;

FIG. 2 is a side View, partly in section, illustrating a portion of the apparatus of FIG. 1 in more detail;

FIG. 3 is a plan view of the apparatus of FIG. 1;

'FIG. 4 is a view, partly in elevation and partly in section, illustrating one form of the valve means and connectedtherewith for connecting the pressuriza-ble flexible bag of this invention for use in the discharging of the sand or other material from the bag at high velocity; and

FIG. .5 is a sectional View taken on line 5-5 of FIG. 4 and further illustrates the structure thereof.

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In the drawings, the letter A designates generally the apparatus of this invention which is used for carrying out the method of this invention. Such apparatus A includes a pressurizable flexible bag B which is so constructed that it is capable of being filled, or partially filled, with sand or other material, then shipped in transit to a point of use, and pressurized with air or other gas under a pressure above atmospheric pressure. At the point of use, the apparatus A includes a means F for supporting or suspending the flerible bag B in a position for the discharge of the sand or other material therefrom. Air, gas or other fluid under high pressure is used for the discharge of the sand or other material from the bag vB under high pressure and velocity for the purpose of cleaning a surface such as metal to remove paint, grease, dirt, inill scale and for performing numerous other operations of such type.

In the preferred form of this invention, the pressuriza-ble flexible bag B is made of rubber or other similar resilient material, preferably having nylon fabric reinforcement embedded therein for strength purposes. In any event, the material forming the walls of the flexible bag B must be able to withstand the pressurizing of the bag B above atmospheric pressure, and preferably in the neighborhood of about 200 p.s.i. of air pressure. The bag also is constructed so that it is substantially flat when deflated so that it can be readily shipped in large quantities when the bag B is empty.

The upper end of the bag B preferably has a plate 10 formed of steel or hard rubber which is secured to the walls of the bag B so as to be integral therewith. Such plate 10 has a hook opening 10a formed therein for receiving a hook 12 or other similar supporting element, as

will be more fully explained. The upper end of the bag B also preferably has an air inlet fitting 14 to which a hose 16 (FIG. 1) is adapted to be connected for the pressurizing of the bag B. The fitting 14 is provided with a one-Way valve internally thereof, or a removable threaded cap which is in place during the use of the bag B for the shipping of the sand or other abrasive.

The lower end of the bag B is preferably tapered or shaped 'conically (FIGS. 1, 4 and 5) so as to provide a funnel shaped lower end for the feed of the sand or other abrasive when the bag B is suspended in the substantially vertical position on the support frame F as shown in FIG. 1. The lower end of the bag B has a valve means V secured thereto by any suitable connecting means. As shown in particular in FIGS. 4 and 5, the valve means V may be formed with an integral tubular body 2% and a conical upper body 22. The conical upper body 22 preferably is disposed within the lower funneled shaped portion of the bag B and is bonded thereto by a suitable adhesive or is connected by rivets or other attaching means sutficient to withstand the pressures encountered in the use of the bag B. The tapered conical opening 22a is in communication with the opening 20a in the bore of the body 20 of the valve means V so that the sand or other abrasive S within the bag B may be fed by gravity or pressure from the interior of the bag B through the tapered opening 22a to the bore 20a. A sliding gate valve element 25 is mounted in the valve body 20 for lateral movement from a closed position to an opened position. The valve element 25 has a round opening 25a therein which is adapted to be moved into alignment with the bore Zita to open the valve means V. Such open position is illustrated in FIG. 5 of the drawings. When the valve element 25 is moved to the left as viewed in FIG. 5, the element 25 closes the bore 20a to prevent the sand or other abrasive from being discharged from the bag B. The bag B is normally closed by the valve element 25 during the transportation and handling of the bag B. The element 25 preferably has stops 25b and 250 at each end thereof to limit its movement. Also, the valve element 25 may be looked in either the opened or the closed position by any suitable means (not shown). The lower end of the valve body 20 is preferably tapered as indicated at 20b to facilitate the positioning of the valve means V in operative position with respectto a discharge means D, as will be more fully explained.

The valve body 20 has threads 20c thereon for threaded engagement with a nut 26. The nut 26 is adapted to be engaged by clamping arms 27 on the discharge device ,D (as shown in FIG. 4). The nut 26.,is adjustable for accurately positioning. same with respect to the inwardly extending projections 27a of each of the arms 27 so that the .surface 20b fits securely and seals with an inclined surface 30a in the body 30 of the discharge device D.

(FIG. 4

The discharge device body 30 provides an internal chamber 31 for receiving the sand or-abrasive from the bag B when the valve means V is in the open position. A venturi means extends through the discharge device D and includes an inlet pipe 35-having a restricted opening at its inner end 35a adjacent to a flared venturi flange36a on an outlet tube 36.. Air or other gas underpressure is,

introduced into the chamber 31 through the pipe 35 so that the sand or otherabrasive in the chamber 31 is picked up and caused to flow with the air or gas under pressure through the outlet tube 35 at a predetermined rate. The rate at which the sandor other abrasive is caused to flow with-the air or gas so as to be discharged from the tube 36 at a high velocity, is subject to control by the move- 1 ment of the inlet tube 35 with respect to the venturi 36a on the outlet tube 36. The tube 35 'is slidably mounted in the chamber 31 through an opening 3% in thebody 34). Threads 35b are provided on the external surface of the inlet pipe 35 and a nut 38 having wing handles 38a is threaded on such threads 3511 forlimiting the inward extent of the movement of the tube or pipe 35. The pipe 35 also has a flange 350 which is for confining a spring 39 under compression so as to constantly urge the pipe 35 inwardly. The extent of the inward movement of the pipe 35 is limited by the position of the nut 38. Thus, the relative location of the opening 35a with respect to the venturi flange 36a may be closely controlled by a shown).

movement of the nut 38 to either move the tube 35 inr wardly or outwardly. Therefore, the amount of the sand or other abrasive which is'di scharged at the high velocity through the outlet tube 35 may be controlled by the adjustment of the nut 38. Other adjustment means and controls for regulating the feed or discharge of the sand or other abrasive from the bag B may be provided, as will occur to those skilled in the art.

The frame Fmaytake numerous forms, one form of which is illustrated in FIGS. 13.' Thebase of the frame F is preferably formed with hollow pipes or tubes 40 and 41 which extend substantially parallel to each other and which are closed at their ends so as to form hollow tanks for holding air under pressure, Also, it is desirable to interconnect such tanks or base tubes 40 and 41 with laterally extending pipes 42 and 43. A base plate 45 may be providedtfor strength and convenience in the positioning of .the discharge device D thereon. the tanks 49 or 41 has an inlet 60a connected thereto for the inletof air or gas under pressure. A fitting 49b 'is provided at one of the tanks 40 so as to connect the flexible hose 16 thereto for supplying the air or gas under pressure to the bag 'Bto pressurize same. Also, another fitting 400 (FIG. 3) is provided for a second flexible 60 One of.

In order to support the flexible bag B, or a plurality of such bags B for the discharge of the sand or other abrasive material from the bag at high velocity, the frame F includes angular upwardly extending frame members 50 which are welded or otherwise connected together by a top plate or pipe 51. Preferably two of such A structures are provided with the frame F. The two or more A-frame structures are interconnected by an I beam which is preferably welded to the top members 51 to form an integral frame structure F. The lower flange 55a of the track-way or beam 55 serves asthe support and guide for rollers 56 of a movable hoist support having side; plates 57 connected thereto. The plates 57 are connected with a pulley or reel 58 having a chain or other member 59 mounted thereon. Such chain 59 is adapted to be reeled and unreeled from the pulley or drum 58.by means of a hand crank 60 or a conventional air driven motor (not is adapted to engage in the plate 10, as previously. explained to support the bag B in the substantially vertical position. Also, the apparatus A preferably includes at least one other hoistingmechanism having another chain 59 which is shown at the right in FIG. 1 for receiving a second flexible bag shown in dotted lines in FIG. 1 while the first flexible bag B-shown in solid lines is in use for a sand blasting operation. Thus, :one bag B maybe hauled or delivered to the apparatus A on any suitable vehicle such-as indicated in dotted. lines and designated by the letterT in FIG. 1. Without requiring any appreciable manual effort, theplate 10 may be engaged by the hook 1.2 to thereby enable the bag B to be lifted upwardly as the chain or line 59 is reeled upon :the pulley or drum58;

After the bag B has been suspended ,in the substantially vertical position it is moved into the position for useito In carrying out the method'of this invention, preferably employing the apparatus-heretofore described, the sand or other abrasive is put into the flexible bag B at the source of the abrasive, or at the place at which the abrasive is classified and prepared for blasting use. The abrasive is put into the flexible bag B by opening the valve 25 to the position shown in FIG. 5, but while the bag B is inverted as compared to the position shown in the drawings. When the desired quantity of abrasive is in the bag B, the valve 25 is closed. It will be understood that the fitting 14 is closed by a suitable threaded cap or any other means which will prevent the abrasive from being discharged from the bag B at that points The bag B is preferably made large enough to hold abrasive in quantities of 500 pounds up to 1000 pounds, and even higher in some instances, thereby eliminating the cumbersome handling of smallbags which has been the case in the past.

The bags B with their contents are then transported by rail, truck or any other suitable transport means. to the distributor or point of use. Ultimately, at the point of use,-the bag B is placed in a substantially vertical position, as explained heretofore in connection with the apparatus of FIGS. 1-5 and is pressurized and connected with the fluid under pressure for metering the sand or abrasive at high velocity for surface cleaning operations. p

After the quantity of the aggregate in the particular bag B "in use has been depleted, the bag Biis then deflatedand flattened out for shipment back to the original station for again filling same for repeated usage. Thus, the bag B of this invention is adapted to be repeatedly. used and is readily shipped back to the initial point of use with a very small space requirement because of its flattened condition.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size,.shape and materials, as well as in the The hook 12 at the lower end of the chain 59 I details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. An apparatus for use in blasting with an abrasive,

comprising:

(a) a pressurizable flexible bag having flexible walls forming the body thereof and being of suflicient strength to Withstand pressures above atmospheric pressure,

(b) means for opening said bag for introducing abrasive material into said bag and for subsequently discharging same therefrom,

(c) means for closing said bag after the insertion of the material into the bag, and

(d) means for introducing fluid under pressure into said bag for feeding the material therefrom under pressure.

2. An apparatus for use in blasting with an abrasive,

comprising:

(a) a pressurizable flexible bag having flexible walls forming the body thereof and being of suflicient strength to withstand pressures above atmospheric pressure,

(b) valve means for opening and closing said bag for the introduction of material into said bag and the discharge of material therefrom, and

(0) means for attaching a source of fluid pressure to said bag for pressurizing said bag above atmospheric pressure.

3. An apparatus for use in blasting with an abrasive,

comprising:

(a) a pressurizable flexible bag having flexible walls forming the body thereof and being of suflicient strength to withstand pressures substantially above atmospheric pressure,

(b) valve means for opening and closing said bag for the introduction of material into said bag and the discharge of material therefrom,

(0) means for attaching a source of fluid pressure to said bag for pressurizing said bag above atmospheric pressure, and

(d) means adapted to be connected to said valve means for discharging the material from said bag under pressure to blast against surfaces for cleaning or other purposes.

4. An apparatus for use in blasting with an abrasive,

comprising:

(a) a pressurizable flexible bag having flexible walls forming the body thereof and being of suflicient strength to Withstand pressures substantially above atmospheric pressure,

(b) valve means for opening and closing said bag for the introduction of material into said bag and the discharge of material therefrom,

(0) means for attaching a source of fluid pressure to said bag for pressurizing said bag above atmospheric pressure,

(d) means for suspending said bag in a substantially vertical position with said valve means at the lower end, and

(e) means adapted to be connected to said valve meansfor discharging the material from said bag under pressure to blast against surfaces for cleaning or other purposes.

5. An apparatus for use in blasting with an abrasive,

comprising:

(a) a pressurizable flexible bag having flexible Walls forming the body thereof and being of sufficient strength to Withstand pressures substantially above atmospheric pressure,

(b) valve means for opening and closing said bag for the introduction of material into said bag and the discharge of material therefrom,

(0) means for attaching a source of fluid pressure to said bag for pressurizing said bag above atmosphenc pressure,

(d) means adapted to be connected to said valvemeans for discharging the material from said bag under pressure to blast against surfaces for cleaning or other purposes, and

(2) said means in paragraph ((1) including (1) a chamber adapted to receive material from said bag through said valve means, and

(2) a venturi in said chamber for the flow of air under'pressure therethrough for picking up material in the chamber and discharging it at a high velocity,

6. An apparatus for use in blasting with an abrasive,

comprising:

(a) a pressurizable flexible bag having flexible walls forming the body thereof and being of sufiicient strength to withstand pressures substantially above atmospheric pressure,

(b) valve means for opening and closing said bag for the introduction of material into said bag and the discharge of material therefrom,

(0) means for attaching a source of fluid pressure to said bag for pressurizing said bag above atmospheric pressure,

(d) means adapted to be connected to said valve means for discharging the material from said bag under pressure to blast against surfaces for cleaning or other purposes, and

(e) said means in paragraph (d) including (1) a chamber adapted to receive material from said bag through said valve means,

(2) a venturi in said chamber for the flow of air under pressure therethrough for picking up material in the chamber and discharging it at a high velocity, and

(3) means for adjusting the venturi opening for regulating the rate at which material is discharged from the chamber.

7. A method of handling and using an abrasive for surface-blasting, comprising the steps of:

(a) intorducing a desired quantity of an abrasive into a pressurizable flexible bag,

(b) closing said bag, and

(c) thereafter pressurizing said bag above atmospheric pressure.

8. A method of handling and using an abrasive for surface-blasting, comprising the steps of:

(at) introducing a desired quantity of an abrasive into a pressurizable flexible bag,

(b) closing said bag,

(0) thereafter pressurizing said bag above atmospheric pressure, and

(d) discharging the abrasive from the bag at high velocity.

9. A method of handling and using an abrasive for surface-blasting, comprising the steps of:

(a) introducing a desired quantity of an abrasive into a pressurizable flexible bag,

(b) closing said bag,

(0) transportaing said bag to its point of use, and

(d) thereafter pressurizing said bag above atmospheric pressure.

10. A method of handling and using an abrasive for surface-blasting, comprising the steps of:

(a) introducing a desired quantity of an abrasive into a pressurizable flexible bag,

(b) closing said bag,

(0) transporting said bag to its point of use,

(d) thereafter pressurizing said bag above atmospheric pressure, and

(e) discharging the abrasive from the bag at high velocity.

I '7 8. References Cited by the-Examiner 2,909,383 10/ 59 Nanfeldt 5l12 X UNITED STATES, PATENTS 2,938,305 Bipes 51-12 10/28 Bassett X, Y 5, 68 12/60 Baucylem 222-193 11/41 Roselle 51J2 11/45 Bick 51V 12 5 LESTER M. SWINGLE, Primary Exammer.

5/57 .Bateman 222-215 FRANK H. BRONAUGH, Examiner. 

1. AN APPARATUS FOR USE IN BLASTING WITH AN ABRASIVE COMPRISING: (A) A PRESSURIZABLE FLEXIBLE BAG HAVING FLEXIBLE WALLS FORMING THE BODY THEREOF AND BEING OF SUFFICIENT STRENGTH TO WITHSTAND PRESSURES ABOVE ATMOSPHERIC PRESSURE, (B) MEANS FOR OPENING SAID BAG FOR INTRODUCING ABRASIVE MATERIAL INTO SAID BAG AND FOR SUBSEQUENTLY DISCHARGING SAME THEREFROM, (C) MEANS FOR CLOSING SAID BAG AFTER THE INSERTION OF THE MATERIAL INTO THE BAG, AND (D) MEANS FOR INTRODUCING FLUID UNDER PRESSURE INTO SAID BAG FOR FEEDING THE MATERIAL THEREFROM UNDER PRESSURE. 